What do the following two equations represent? $-x-3y = 1$ $x+3y = -1$
Solution: Putting the first equation in $y = mx + b$ form gives: $-x-3y = 1$ $-3y = x+1$ $y = -\dfrac{1}{3}x - \dfrac{1}{3}$ Putting the second equation in $y = mx + b$ form gives: $x+3y = -1$ $3y = -x-1$ $y = -\dfrac{1}{3}x - \dfrac{1}{3}$ The above equations turn into the same equation, so they represent equal lines.